MercoPress. South Atlantic News Agency

New strain of bird flu has capacity to mutate rapidly; could become transmissible among humans

Professor Marion Koopmans: “the virus is spreading under the radar”

The new strain of bird flu that has killed 17 people in China has been circulating widely “under the radar” and has acquired significant genetic diversity that makes it more of a threat, warned scientists.

Dutch and Chinese researchers who analyzed genetic data from seven samples of the new H7N9 strain say it has already acquired similar levels of genetic diversity as much larger outbreaks of other H7 strains of flu seen previously in birds.

“The diversity we see in these first few samples from China is as great as the diversity we have seen with a large outbreak in the Netherlands several years ago and one in Italy,” said Marion Koopmans, head of virology at the Dutch National Institute for Public Health and the Environment, who worked on the study as part of a nine-member team.

”This means it (the H7N9 strain in China) has been spreading quite a bit and it's important to understand where exactly that is going on.“

Its genetic diversity shows the virus has an ability to mutate repeatedly and is likely to continue doing so, raising the risk that it may become transmissible among humans.

Koopmans, whose research was published in the online journal Eurosurveillance, said the circulation would probably have taken place in either birds or mammals, but said exactly which animals were involved was not yet clear.

”Simply the fact that this virus is spreading under the radar - because that is what this data confirms - is of concern,” she told reporters in a telephone interview.

The H7N9 virus is so far known to have infected 87 people in China, killing 17 of them. Health officials raised further questions on Friday about the source of the new strain after data indicated that more than half of patients had had no contact with poultry.